Finish composition for application to a continuous filament polypropylene sheet

ABSTRACT

A FINISH COMPOSITION IS PROVIDED FOR APPLYING TO A SPUNBONDED CONTINUOUS SILAMENT POLYPROPYLENE SHEET INTENDED FOR USE AS A PRIMARY CARPET BACKING. THE FINISH COMPRISES A MIXTURE OF TWO POLYSIOXLANE COMPONENTS IN A RATIO FROM 9:1 TO 1:9 BY WEIGHT; THE FIRST SAID COMPONENT BEING A DYEABLE COMPONENT COMPRISING A PRIMARY OR SECONDARY AMINOALKYLPOLYSILOXANE OR AMINOALKOXYALKYLPOLYSILOXANE FLUID HAVING AN AMINE FUNCTIONALITY IN THE RANGE 4-7%, AND BEING SUBSTANTIALLY FREE FROM OTHER REACTIVE GROUPS; AND THE SECOND SAID COMPONENT BEING A LUBRICANT COMPONENT COMPRISING A POLYDIALKYL/ARYLSILOXANE FLUID HAVING HYYDROXYL END GROUPS AND BEING SUBSTANTIALLY FREE FROM OTHER REACTIVE GROUPS.

United States Patent Ofice 3,766,115 Patented Oct. 16, 1973 U.S. Cl. 260-291 SB 6 Claims ABSTRACT OF THE DISCLOSURE A finish composition is provided for applying to a spunbonded continuous filament polypropylene sheet intended for use as a primary carpet backing. The finish comprises a mixture of two polysioxlane components in a ratio from 9:1 to 1:9 by weight; the first said component being a dyeable component comprising a primary or secondary aminoalkylpolysiloxane or aminoalkoxyalkylpolysiloxane fluid having an amine functionality in the range 4-7%, and being substantially free from other reactive groups; and the second said component being a lubricant component comprising a polydialkyl/arylsiloxane fluid having hyydroxyl end groups and being substantially free from other reactive groups.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to a finish composition for application to a nonwoven fibrous sheet material. More particularly, the invention is directed to a finish containing selected polysiloxanes for application to a spunbonded continuous filament polypropylene primary carpet backing, which confers both tintability in competition with acidor direct-dyeable face fibers, and lubricity to facilitate survival of tufting without substantial strength loss.

(2) Description of the prior art U.S. Pats. 3,563,838 and 3,502,538 describe spunbonded continuous filament polypropylene fibrous sheet products useful as primary carpet backing which offer advantages over jute backings in such properties as dimensional stability, uniformly, supply stability, hydrophobicity, improved tufting pattern regularity, and nonraveling of cut edges.

U.S. Pat. 3,322,607 discloses a class of lubricant finishes for such spunbonded continuous filament polypropylene products which facilitate needle penertation during carpet tufting, thereby preserving the good tensile properties of the spunbonded nonwoven backing through the tufting operation.

Lubricated spunbonded polypropylene primary carpet backings are particularly well suited for certain tufted carpet styles, e.g., high density contract carpeting, where the lack of tintabiltiy of the polypropylene backing by the dyes customarily employed for tinting the face yarns is of little concern since the backing is completely obscured by the face yarns. However, in other less densely tufted carpet styles where the backing is not so completely obscured by the face yarns, it is highly desirable that the backing the tintable to more closely match the color of the face yarns in order to prevent grin through of the back- U.S. Pat. 3,545,909 discloses a class of aminoalkylsilane and siloxane coloring assistants which may be applied to difficultly dyeable fibrous substrates in order to render them tintable with various pigments and/ or acid dyes. Although application of such coloring assistants to spunbonded polypropylene primary carpet backings would be expected to confer tintability by the same acid or direct dyes employed for tinting the nylon or cotton face fibers customarily employed in tufted carpets, it has been discovered that such finishes in general fail to also provide the degree of lubricity required for satisfactory tuftability of the spunbonded polypropylene backings. Although U.S. Pat. 3,322,607 discloses that these coloring assistants may be combined with lubricants, it has now been discovered that most of these coloring assistants unfortunately also destroy or seriously impair the function of conventional lubricating agents blended or mixed with the coloring assistants in efforts to achieve sufficient lubricity for satisfactory tuftability. In addition, it has further been discovered that only a very limited number of the numerous members of aminoalkylsilane or siloxane coloring assistants olfer sufiiciently facile tintability to compete effectively with the tintability of the face fibers, and also to adhere teuaciously enough to the polypropylene fibrous substrate to survive customary carpet dyeing procedures, while simultaneously being non-antagonistic toward the lubricant additive, but still compatible therewith. All of these objectives, plus other criteria described below, are met by the critical selection of finish components provided by the present invention.

SUMMARY OF THE INVENTION This invention provides a finish composition for application to a spunbonded continuous filament polypropylene sheet, intended for use as a primary carpet backing, comprising a mixture of two polysiloxane components in a ratio from 9:1 to 1:9 by weight; the first said component being a dyeable component comprising a primary or secondary aminoalkylor aminoalkoxyalkyl-polysiloxane fluid having an amine functionality in the range 4-7%, and being substantially free from other reactive groups; and the second said component being a lubricant component comprising a polydialkyl/arylsiloxane fluid having hydroxyl end groups and being substantially free from other reactive groups. When this finish is applied at a level of about 28% by Weight to a spunbonded polyproplene sheet, such as a primary carpet backing, the nonwoven backing retains high strength after tufting and is tintable by acid and direct dyes in competition with nylon and/ or cellulosic tufted face fibers.

Also provided are polypropylene sheets that have been treated with the finish composition.

DETAILED DESCRIPTION OF THE INVENTION The spunbonded nonwoven sheets treated with the finish of this invention are composed of continuous filaments of isotactic polypropylene, preferably of the type disclosed in Petersen U.S. 3,502,538 with respect to bonded structure, and/ or of the type disclosed in Edwards US. 3,563,- 838 with respect to preferred alignment of filaments in the length and width directions.

The dyeable and the lubricant components of the finish of this invention are polysiloxane fluids, by which is meant polymeric materials whose backbone chain is composed essentially of units.

Values of n of about l0 50 are preferred, such compounds having fluid viscosities suitable for direct application to the fibrous spunbonded substrate by conventional means such as gravure roll coating, spraying, dipping, etc. Polysiloxanes with higher values of u may also be employed by diluting them with suitable inert materials to provide a solution of suitable viscosity for application to the nonwoven substrates.

The dyeable polysiloxane component must be a primary or secondary aminoalkylor aminoalkoxyalkyl-polysiloxane with an amine functionality in the range 47%,

and be substantially free of other reactive groups. These materials are preferably copolymerseither of the block or random varietyat least some of whose silicon chain atoms bear aminoalkyl side chains to provide the requisite amine functionality, where the amino group is separated from the silicon atom by at least three carbon atoms of the alkyl or alkoxyalkyl side chain. Each alkyl or alkoxyalkyl group may contain up to 21 carbon atoms, but preferably they each contain 6 carbon atoms or less. Thus, the aminoalkylpolysiloxanes or aminoalkoxyalkyl-polysiloxanes may be represented by the recurring structural unit where R and R, individually, are selected from alkyl of l-20 carbon atoms,

alkoxyalkyl of 2-20 carbon atoms, aminoalkyl of 3-20 carbon atoms, and aminoalkoxyalkyl of 3-20 carbon atoms,

with the proviso that the amino group is separated from the Si atom by at least 3 carbon atoms, and with the proviso that the amino group is NH NHR" or NHRNH in which R" is an alkane radical of 1 to 6 carbon atoms. Usually, the polysiloxane will be endcapped with alkyl groups of 1-6 carbon atoms. Tertiary amine polysiloxane compounds are not included since they lead to coated polypropylene substrates which, though readily initially tintable, lose substantially all their color during the full course of normal tufted carpet dyeing processes.

The amine functionality is computed as the weight percent of NH or NH groups present in the polysiloxane. Polysiloxanes with amine functionalities less than 4% lead to insufficient levels of tintability as well as lack of permanent retention of tint on the substrate through the full carpet dying process. Polysiloxanes having amine functionalities in excess of 7% tend to be too reactive for convenient application to the nonwoven substrate, as well as leading to substantial damage i.e., fiber breakage and loss of tensile strength during subsequent tufting which cannot be adequately counteracted by addition of lubricant components. Similar tufting damage occurs if the dyeable polysiloxane component contains appreciable quantities of other reactive groups such as Si-alkoxy groups which can react with the terminal hydroxyl groups of the lubricant polysiloxane component to form crosslinks, thus severely impairing its lubricating ability.

These several requirements are at least consistent with the observed phenomena and with the following hypotheses:

(l) The amino groups furnish sites for attachment of the acid dye molecules, and a minimum number (amine functionality at least 4%) is required for suflicient dye pickup to furnish adequate tintability in competition with the tufted face fibers.

(2) The amino siloxanes react with atmospheric carbon dioxide and/or moisture to yield stabilized crosslinked networks. This reaction manifests itself as a gradual increase in viscosity and turbidity when the finish composition is exposed to ambient atmosphere and also in that when the finish compositions of this invention are applied to the non-woven substrates, a surface tackiness is observed to develop gradually, and finally disappear as the course of cross-linking proceeds. Maximum tackiness occurs relatively promptly (delays of about 1-3 days) for finishes with high proportions of dyeable components having high amine functionalities; delays of up to four weeks occur for those finishes having low proportions of dyeable component. Furthermore, the adhesion of the aminoalkylpolysiloxane as initially applied to the polypropylene substrate appears to be low, and therefore, a certain minimum level of post-application cross-linking (amine functionali y at least 4%) app ars to be necessary to sufficiently immobilize and lock the dyeable component onto the fibers in order to resist removal during subsequent carpet dyeing treatment. On the other hand, amine functionalities in excess of 7% lead to excessive levels of cross-linking which causes rapid, undesirable, uncontrolled viscosity increases of the finish on exposure to the ambient atmosphere thus interfering with subsequent application of the finish to the fibrous substrate. Excessive levels of amine functionality can also lead to undesirable water solubility of the dyeable component.

(3) When reaction between dyeable component and lubricating component occurs to any appreciable degree (as between alkoxy silicon substituents on the dyeable component and hydroxyl end groups on the lubricant component) the efficiency of the lubricant is destroyed and/ or additional cross-linking and undesirable fiber immobilization in the substrate occurs. Of course, scrupulous purification of the finish ingredients from all traces of extraneous reactive groups is not necessary, since minor interaction and reaction can be tolerated without excessive loss of lubricating ability.

The preferred dyeable component is a random copolymer having an amine functionality of 5.8% represented by the following empirical formula wher Me stands for methyl:

J Lll lle Jan LC4Ha-NH2 is Preferred also are the polysiloxanes containing only alkyl and aminoalkyl groups.

The lubricant component of the finish of this invention is a polydialkyl/arylsiloxane having hydroxyl end groups and being substantially free of other reactive groups. It is desirable that the lubricant component be a polysiloxane, like the dyeable component, in order that they be fully compatible for ease of mixing, storage stability, and uniformity of application. Furthermore, it is necessary that the lubricant polysiloxane have essentially all its backbone chain silicon atoms disubsituted with inert alkyland/or aryl-groups, since unsubstituted Si-H groups are sufiicient- 1y reactive in the presence of the dyeable polysiloxane component to destroy lubricity.

These polydialkyl/arylsiloxanes having hydroxyl end groups are compatible with and are inert toward the dyeable component. Each alkyl group may contain up to 21 carbon atoms, while each aryl group may contain up to 11 carbon atoms. It is essential that the lubricant polysiloxane component have hydroxyl end groups. Commercially available polydimethylsiloxanes, e.g., Union Carbides L- 45 or Dow-Cornings DC-200, commonly have alkyl end groups, and although they provide lubricity for tufting purposes when used with the dyeable component and are inert toward the dyeable component, finishes containing polysiloxanes having alkyl end groups lead to carpets which are scroopy under foot, i.e., the carpet pile has an annoying crunchy feel when walked upon. It is postulated that during the dyeing process some of the polydialkyl/ arylsiloxane transfers from the backing to the pile fibers, which are incompletely wet by such a lubricant, thus leading to a stick-slip scroop-producing mechanism under load. In marked contrast, the hydroxyl end-grouped polydialkyl/arylsiloxanes do not lead to scroopy products, presumably either because they do not transfer to the pile fibers or because they wet the pile fiber more completely and uniformly. Apart from the necessary hydroxyl end groups, polydialkyl/arylsiloxane lubricant components sh0uld-like the dyeable componentsbe substantially free from other reactive groups.

Thus, the lubricant polydialkyl/arylsiloxane having hydroxyl end groups can be represented by the structure wherein R" and R" individually are selected from alkyl of up to 21 carbon atoms or aryl of up to 11 carbon atoms.

The dyeable component and the lubricant component should be mixed in a weight ratio in the range from 9:1 to 1:9, i.e., each component must be present at a level of at least 10% in the finish in order to perform its function adequately. Ratios in the range between 7:3 and 3:7 are preferred. Each component may consist of more than one species if desired, e.g., the lubricant component may consist of a blend of hydroxyl-ended polydimethylsiloxane, polydiethylsiloxane, polymethylethylsiloxane, polymethylphenylsiloxane, etc., in any proportion. Alternatively, each component may consist of one or more copolymers comprising species within the specified limitations.

As mentioned above, the finishes of the present invention may be applied to the polypropylene spunbonded primary carpet backing by any convenient means, e.g., roll coating, spraying, dipping, etc. and adequate tintability and lubricity will be provided with finish add-ons in the range from about 2-8%. Ordinarily, add-ons at the lower end of this range are preferred for reasons of economy. Alternatively, the dyeable and lubricant components may be applied to the primary carpet backing independently at individual rates which lead to appropriate total pickup and appropriate component ratios. It may also be desirable, particularly for continuous commercial operation, to blanket the coating equipment and finish reservoir with an inert atmosphere (e.g., dry nitrogen gas) to delay commencement of the crosslinking reactions described above.

The effectiveness of a tufting lubricant may be determined by tufting the lubricated sheet and measuring the tear strength of the tufted sheet, the more effective the lubricant, the higher the tear strength. In the following examples, lubricant elfectiveness was measured by tufting the lubricated sheets on a table-top tufter with 2600 denier bulked continuous filament nylon yarn, at 7 tufts/ inch (in the machine or length direction) the tufts being spaced inch apart in the width direction and having a height of inch.

The machine direction tufted tongue tear strength was measured in the following manner. The tufted nonwoven sheet is cut into a sample six inches wide (cross-machine direction, across tufting rows) and eight inches long (machine direction along tufting rows). The sample is cut in the center of the width four inches in the machine (tufting) direction. The sample is mounted in an Instron tester using 1.5 inch by 2 inch serrated clamps. With a jaw separation of 3 inches, one side of the sample cut is mounted in the upper jaw and the other side of the sample cut is mounted in the lower jaw. The sample is uniformly spaced between the jaws. The full scale load is adjusted to a value greater than the tear strength expected for the sample. Using a cross head speed of 12 inches per minute and a chart speed of 10 inches per minute, the Instron is started and the sample is torn. An average of the three highest stresses during tearing is taken. The tongue tear strength in pounds is reported as this average divided by 100 and multiplied by the full scale load. In general several determinations are made and the average reported.

Dyeability of the tufted samples in the following examples is evaluated by visual examination of the intensity of tint of the backing achieved. The dyeing procedure, using 1% Merpacyl Red is as follows (the bath-to-carpet weight ratio should be about 20:1 to 40:1 and the percent chemicals are based on the total weight of carpet).

(1) Set bath at 80 F. with:

Percent Organic sequestering agent of the tetrasodium salt of ethylenediaminetetraacetic acid (EDTA) 0.25 Alkanol ND dyeing assistant (anionic) 1.0 Merpol OJS surface active agent (nonionic) 0.5 Trisodium phosphate (TSP) 0.5

(2) Run 10 minutes in an alkaline bath to remove finish from the BCF nylon yarn.

(3) Add 1.0% monosodium phosphate (MSU).

(4) Adjust to pH 6.2i0.2 with acetic acid.

(5) Run 10 minutes.

(6) Add dissolved dye slowly (over 15 minute period).

(7) Run 15 minutes at F.

(8) Raise to 130 F. at 29 F./minute.

(9) Raise to 205 to 210 F. at 3 =F./minute.

(10) Check pH and maintain at 6.2102 throughout the dyeing.

(11) Dye for 60 minutes at 205 to 210 F.

(12) Drop bath and rinse cold F. or lower).

The following examples illustrate the use of the preferred finishes of this invention and demonstrate the criticality of the selection of the proper component ingredients. All compositions in these examples are given as percent by weight. In the formulas Me represents methyl and Et represents ethyl.

EXAMPLE I This example illustrates the preferred ratios of dyeable and lubricant components in the finishes of this invention.

A dyeable random copolymeric aminoalkylpolysiloxane having the empirical formula and an amine functionality of 5.8% is blended with various proportions of a lubricant hydroxyl-ended polydialkylsiloxane component represented by the formula to prepare the several finish compositions listed in Table I. There are applied by a hand-held gas propelled atomized spraying technique at a weight pickup of 4% as uniformly as possible across the face of sample sheets of 3.5 oz./yd. spunbonded continuous filament polypropylene nonwoven primary carpet backing meeting the bonding limitations of U8. 3,502,538 and the filament directionalities limitations of US. 3,563,838. These samples are subsequently placed for ten minutes in a circulating air oven at C. and are then tufted with nylon face yarn and subsequently pot dyed by the procedure described above.

The data in Table I indicate that fair dyeability (i.e., a moderate depth of tint) of the polypropylene backing in competition with the deeply tinted nylon face yarn is observed when 10% of the dyeable component is present, and that more intense tinting occurs as the proportion of the dyeable component is increased. The tufted tongue tear data indicate, however, that severe strength loss occurs when the lubricant component is completely absent, and that substantial improvement occurs when 10% or more of the lubricant component is present. Accordingly, the preferred finishes comprise blends of components in the range 9:1 to 1:9. The data also indicate that the optimum compromise between tintability of the backing and strength retension through tufting occurs for dyeable component to lubricant component ratios from about 7:3 to 3:7. It has also been found from additional dyeing experiments employing more rigorous Beck dyeing or paddle dyeing processes as employed in some cases for commercial carpet production, that best tint retention on the backing is obtained in these cases with 7:3 ratio finishes, and these are accordingly most preferred.

EXAMPLE II This example illustrates the criticality of the various structural parameters used in defining the dyeable polysiloxane components of this invention.

Run 1 A test carpet sample is prepared according to the procedures of Example I, excepting that the dyeable po ysiloxane component chosen is a random copolymer similar to that of Example I having, however, a lower proportion of the aminoalkylsiloxane constituent which therefore provides an amine functionality of only 2%, i.e., less than the 4% minimum amine functionality required for the dyeable polysiloxane components of the finishes of this invention. Even through a high value of 8:2 for the dyeable componentzlubricant component ratio is employed, the observed dyeability of the polypropylene backing is rated only poor.

Run 2 Similar test carpet samples are prepared employing as the dyeable component candidate a tertiary aminoalkylpolysiloxane (which is therefore outside the limits of the present invention) of the following composition:

Me Me Two interesting observations are made on these test samples: First, substantial tinting of the polypropylene backing does occur initially on introduction of the sample into the dye bath, but this tint is not retained on the backing throughout the full dyeing procedure and the sample leaves the dye bath with the polypropylene backing essentially untinted (similar behavior has been observed for other tertiary amine dyeable component candidates). Second, satisfactory tufting of these samples Without substantial strength loss is effected even when no lubricant polysiloxane component is mixed with the tertiary aminoalkylpolysiloxane dyeable component. Both of these observations are consistent with the hypothesis that no substantial carbon dioxide/moisture reaction occurs with such tertiary amine dyeable candidates to provide sufficient post-application cross-linking to anchor the dyeable component permanently on the polypropylene substrate; and further, since no such self-eross-linking occurs, at least this particular tertiary amine polysiloxane can function effectively as a substrate tufting lubricant. However, in spite of this desirable lubricant ability, the fugitive tint retention feature makes these tertiary aminoalkylpolysiloxanes unacceptable as dyeable components for the purposes of the present invention.

Runs 3a and b Two dyeable component candidates comprising random copolymeric polysiloxanes of the following empirical formula are evaluated as finishes on test carpet samples according to the procedure of Example I:

for Run 3a, Z is -OEt; and for Run 3b Z is OSiMe Both of these candidates have reactive ethoxy end groups and/or reactive side chains, and hence fail to meet all the limitations of this invention even though they do ave des P y alkyl ami o side chains a th amine functionalities are in the required range. These two candidates are mixed with the preferred hydroxyl end grouped lubricant of Example I at weight ratios of 9:1 and 8:2, respectively. Although dyeability of the polypropylene backings in both cases is rated at least fair to good, tufted tongue tear values for the samples are an unacceptably low 15 and 13 lbs., respectively, indicating that the excess reactivity of these candidates deleteriously interferes with the ability of the lubricant component to protect the spunbonded backing from severe loss of strength during tufting.

EXAMPLE III This example illustrates the criticality of the various structural parameters employed in defining the lubricant polysiloxane components of this invention.

Run 1 Three test carpet samples are prepared from spunbonded 'backings coated with finishes according to the procedure of Example I wherein the hydroxyl-ended polydimethylsiloxane lubricant component of this invention is replaced by hydrocarbon-ended polydimethylpolysiloxane lubricant candidate (specifically Dow-Cornings DC-ZOO). The test results on the dyed samples are indicated in Table 11.

TABLE II [Results for Runs 2a, b, and c of Ex. III, employing DC-200 lubricant] Tufted Dycable Component tongue DC-200, tear Run From- Percent percent (lbs.) Dyeability 2a Ex. 1-. 70 30 51 Excellent. 2b. Ex. 2, run 3a--.- 10 31 Fair. 20 Ex. 2, run 3b-..- 90 10 30 Good.

In Run 2a, each component functions well in the finish mixture as indicated by the excellent dyeability rating and the excellent tufted tongue tear value. However, this hydrocarbon-ended lubricant is still not acceptable for the purposes of the present invention since the test carpet sample has an unacceptably high level of scroop. In Runs 2b and 2c, the dyeable components provide samples with dyeabilities rating fair to good, consistent with the results of Example II Runs 3a and 3b. Interestingly enough, and in contrast to Example IIs results, the finishes of this example also provide acceptable lubrication of the spunbonded backing during tufting, as indicated by the good values of tufted tongue tear for these two samples. It is postulated that this favorable result occurs because the hydrocarbon-ended polydimethylsiloxane lubricant of this example is so inert that it remains free of deleterious interaction with the dyeable polysiloxane candidates which proved to be too reactive in the finish compositions of Example II, Runs 3a and 3b. Even so, the candidate mixtures of Runs 2b and 2c of this example do not constitute satisfactory finishes for the purposes of this invention, since they also lead to test carpet samples with unacceptably high levels of flscroop'fl 9 EXAMPLE IV This example illustrates preparation of a scatter rug from rayon face fiber tufted into a spunbonded polypropylene backing coated with the finish of this invention and wherein the backing and face fibers are simultaneously dyed with direct dyes.

Rayon face fibers are tufted at seven stitches per inch, inch gauge and inch pile height at a weight of about 14 oz./yd. into a spunbonded polypropylene backing of 2.5 oz../yd. bearing 4.8 weight percent of the 70:30 finish composition of Example I. A self-curing carboxylated styrene-butadiene latex having a surface tension in excess of 45 dynes/centimeter is applied to the back of the sample by kiss-roll coating to provide about 20 oz./yd. of latex pickup after drying 10 minutes at 270 F. (Latices with surface tension in excess of 45 dynes/centimeter are preferred in order to avoid excessive penetration of the latex through a backing which might accordingly obscure the dyeable backing.)

The latexed and cured rug is then placed in an aqueous bath at 100 F. containing surfactants (1.0% Avitex AD plus 0.5% Duponol RA, products of the Du Pont Company). The solution weight to sample weight is chosen to be about 40:1. After 10 minutes, the pH is adjusted to the range 8-9 by adding tetrasodiumpyrophosphate. Next, dye, based on sample weight, is added and the temperature raised to the boil at a rate of 3 F. per minute. After each of two 15 minute intervals, 3 gm./l. sodium chloride is added, and then the solution is cooled to 180 F. and a third increment of 3 gm./l. of sodium chloride is added. The 180 F. temperature is maintained for 30 minutes, and then the dye bath is slowly displaced with water, and the sample then rinsed for 10 minutes in water at 80 F. Next, 5 gm./l. of sodium chloride is added and the temperature raised to 90 F. and held for 15 minutes, the solution is displaced with water, and the sample rinsed minutes at 90 F. The sample is drained, and finally dried at 250 F.

Two separate scatter rugs are dyed by this procedure, one using Pontamine Blue 4GL and the other using Pontamine Yellow 4GL (direct dyes, products of the Du Pont Company). In both samples, the backing as well as the face yarn dyed well, and therefore no backing grinthrough problem exists.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described for obvious modifications will occur to those skilled in the art.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A finish composition for application to a spunbonded continuous filament polypropylene sheet consisting essentially of a mixture of two polysiloxane components in a ratio from 9:1 to 1:9 by weight; the first said component being a dyeable component having an amine functionality 10 in the range of about 4-77, and being represented by the formula where R and R, individually, are selected from alkyl of 1-20 carbon atoms,

alkoxyalkyl of 2-20 carbon atoms, aminoalkyl of 3-20 atoms, and aminoalkoxyalkyl of 3-20 carbon atoms,

with the proviso that the amino group is separated from the Si atom by at least 3 carbon atoms, and with the proviso that the amino group is NH -NHR" or NHRNH in which R" is an alkane radical of 1 to 6 carbon atoms, and wherein n is a a cardinal number of about 10 and 50; and the second component being a lubricant component having hydroxyl end groups and being represented by the formula 5. The composition of claim 4 wherein the lubricant component is hydroxyl-ended polydimethylsiloxane.

6. A spunbonded continuous filament polypropylene sheet having applied thereto from about 2% to about 8% of the finish composition of claim 1.

References Cited UNITED STATES PATENTS 3,545,909 12/1970 Gagliardi 8-13 3,423,314 1/1969 Campbell 117-1395 X 3,322,607 5/1967 Jung 16167 HERBERT B. GUYNN, Primary Examiner U.S. Cl. X.R.

8-85, 172, 1l7138.8 E; 260-465 E, 46.5 G, 825

Po-wa UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 1 66,ll5 Dated October 1 1973 Inventor(s) y Sands It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column-l0, Claim 1, line 1, "A 7" should read r7% i I Colurnn' 10, Claim 1, line 17, "number of about" should readjfnumber between about 001m 10, Claim line 39, in the formula "M should read Me Signed and sealed this 5th day of March l97).

(SEAL) Attest:

EDWARD M.FLETOHER,JR.

' RSHALL DANN Attesting Offmer' x of Patents 

